Cancer is a disease in which cells in the body grow out of control. Cancer and cancer cells are typically named according to the tissue in which the cells start; e.g. when originating in the breast, it is called breast cancer. Breast cancer is the second leading cause of cancer-related deaths in women today and is the most common cancer among women, excluding non-melanoma skin cancers. In 2009, an estimated 192,370 new cases of invasive breast cancer were diagnosed among women, as well as an estimated 62,280 additional cases of in situ breast cancer. In 2009, approximately 40,170 women were expected to die from breast cancer.
The nuclear receptor, estrogen receptor (ER) and progesterone receptor (PR) and their associated steroid hormones, are known to play essential roles in the growth of breast tumors, and their status is also employed as diagnostic indicators for endocrine responsiveness and tumor recurrence. The estrogen receptors (ERs) are attractive targets in the treatment of breast cancer and the development of receptor-based breast cancer imaging agents for diagnostic use in biomedical imaging technique positron emission tomography (PET).
Ecteinascidin-743 (ET-743) is a marine tetrahydroisoquinoline (THIQ) alkaloid isolated from the tunicate Ekteinascidia turbinata with a potent cytotoxic activity against a variety of tumor cell lines in vitro and against several rodent tumors and human tumor xenografts in vivo. Tetrahydroisoquinoline natural products have been shown to exhibit biological activity that renders them as potential pharmaceutical agents. The tetrahydroisoquinoline family of alkaloids includes potent cytotoxic agents that display a range of biological properties such as antitumor and antimicrobial activities studied thoroughly over the past 25 years, starting with the isolation of naphthyndinomycin in 1974. 1-Methyl-1,2,3,4-tetrahydraisoquinoline (1-MeTIQ) is considered to be a possible endogenous Parkinsonism-preventing agent that is present in the mouse, rat, monkey and human.